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Trivector minicomputer / Megatronics disc drives


New Member
Sep 17, 2022
I used to fix the 4A's over twenty years ago. They looked nothing like that system but board layout was quite similar and also using Z80. They had external 8" floppy, tape and 8" hard drives. If I remember correctly they ran BOS. The machines where replaced by DEC PDP-11/73's also running BOS

BOS https://en.wikipedia.org/wiki/Business_Operating_System_(software)
I was computer technician at a college in the UK in the 80s. We had 2 Trivector Triton, each with magnetic tape cartridge backup and 10mb hard drive. Before moving the hard drive you had to lift the back of the drive and tighten a screw to lock the heads. The drives were very unreliable! Our systems definitely ran BOS, and we used MicroCobol for teaching programming. A variety of terminals were connected via RS232


Experienced Member
Jul 5, 2012
Said system is now with me, currently (slowly..) restoring the Diablo drive. The system MB has place for 3 identical Z80 cpu setups, of which 2 are populated. I'd welcome any info on this system, but will not probably go as far as programming in Cobol !


Jun 3, 2014
As noted in a previous posting, the Centre for Computing History (CCH) in Cambridge, UK has an example of the DRI Model 4000 hard drive (Diablo Model 40). The technical manual donated with the drive describes it as ‘series 4000, variant 258-99XX’, and the manual as ‘document reference 4099/issue L’ and ‘part number of technical manual 188-055’.

The history of the Model 4000 drive in the CCH collection is known in outline. It had been ordered for use with an ICL mainframe, possibly the 1900. By the time it was delivered, the mainframe had been superseded, and it was decided the hard drive was no longer appropriate. It was retained by a staff member and was subsequently donated to CCH. It had never been used and arrived at the museum in the original packing materials. There was no exchangeable cartridge with the drive. The DRI Technical Manual is also in the collection at CCH.

The link in the previous posting in this thread was to a DRI Brochure with information regarding the Model 4000 drive at:

Separately, CCH acquired at least one example of the Model 24 (24e) hard drive exerciser, believed to be designed for use with the hard drive:

The photo of the exerciser shows the ‘manufacturer’ as Newbury Data Recording, which reflects a business connection between DRI and Newbury Data.

CCH also has an example of a Trivector, in this case model/version 3:

The Trivector 3 had been used at a Cambridge business and arrived at the museum as part of a larger donation.